Pipe wrench



NOV. 13, 1951 LEONARD 2,574,834

PIPE WRENCH Filed Oct. 8. 1947 JozwnzzvmD Patented Nov. 13, i951 whenSTTES PIPE WRENCH JohnR. Leonard, Washington, C. Application oetobers,1947,'SerialNo.778;590 i cases.- (01. 81-1919.)

This invention relates to a pipe Wrench.

One of the objects (of the invention is .to provide a pipe wrench whichcan get a fast .grip on a pipe that lies close to :a wall, without thenecessity of any part of the wrench being interposed between the pipeand wall.

In the conventional pipe wrench the initial fast grip is Qbtainedby'rotating the wrench through an arc of considerable magnitude. .Whenworking with such a wrench 'upon a pipe which is close to the wall, th'eworking arc may not be substantially greater-than 180,which arc is.fully occupied by the jaws of the wrench whenthey are first placedastride the pipe so that there is no room for any turning movement ofthe wrench in order to get the initial hold on the pipe. Consequently;in such situations it is necessary to break away some of the plasterbehind the pipe, ;so that one of the jaws can be placed back of thepipe, leaving some room at the front through which the wrench can beturned for gripping and turning the pipe. l H p The present inventionprovides a pipe wrench which takes up all lost motion upon being movedrectilinearly to an -einbracing position relative to the pipe, until itis in firm contact-therewith, from which position abiting grip-isimmediately securedat the beginning of the turningrm ovemerit, the majorpart of theturning movenient being usefully employed in turning thepipe.

Another object of the invention .is vto provide a pipe wrench of thetype described,- thejaws of which are tapered to'ward thirfree ends.forwardly of the normal turning center of the wrench, to increase theturning are when wo'rking upon a pipe close to a surface which-nornlally would obstruct the wrench.

A further object of the invention is to provide a pipe wrench asdescribed, in which upon initial turning movement of the wrench in atightening direction, the jaws tilt to positions of tangency to thepipe, forward of the normal diametrical points of tangenc'y at whichthey engage the pipe prior to tightening movement, thereby reducing thewidth of the mouth. of the wrench to less thanthediameter 6f the pipe,so that" the pipe is positively prevented from slipping forward in thejaws, ensuring immediate seizure'of the pipe and maintenance of the gripuntil the wrench is reversely turned in a release direction. a v

Other objects of the invention will appear as the following descriptionof a preferred and practicalembo'diment thereof proceeds.

In the drawings:

Figure 1 is aside sectional view of v a wrench embodying the principlesor the invention, in its initialp'osition with respect to a pipe:

Figure 2 i a side elevation, partly in -sectiony showing the pipeentered between the jaws, but

not gripped;

Figure 3 is taisirr'iilar view showing the pipe is the movable member 4havinga movablewiawl 5, complementary to .the fixed jaw}, said movablejaw. being integral jwithwan adjl ting stem 6, and being disposedsubstantially;at,right, angles thereto. The handlez preferably extendsinia direction perpendicular to the stemdi, that vis,

in a general direction opposite to the mouth ofthe wrench. I V g V I'Ihestem 6 has a series of concave teeth fl on its back face engageablewith a worm 8, ,by m n f wh h th width of th cia oneti e is adjusted. Te wr n his re er y madeto akeo ytwo sizes. p nipejpr mar lv o minimi ethe requisite engt o the m V6 sgth t. th latter w l p o t undu ytw en adu e il a s all p p and sec ndar te r y n th wrench from being usedon apipe tqo large forits str n h and ecomin brok through h of an extensionon its handle v p I H V The stem 6 is slidable through a; guide in thebody ,I. Said guide hastwo-aligned portionss and vtermed apart. The u'en qr i l 94 a channel; openat the front. The lower portion lll is aclose d bore. Flfhefie f .5 .is of uniform os ct o lth e hel t th ex efi of ts .tqol per oa. e n rov ed. wi h sntran Side, fflfis formingchannels ll; w ich fit about projecting i s l e ili "ii i li fin 9 he'iml' ifi sides ofthe fguide channel {land the guide bore lh e inner bck wall or the guideportions Sand 10 he inthe same I engaged by thetoothed rar face of theQstein 6 The body 1 between the ptruans'ejafidlater the Stem guide tilni guide channel!) and theifin'r front face ofthe guide bore I'll. It is forrfid' a recess [3,

opening initsjrrentra',wi er thanitl'iewidth of said guide marina andgiiid bore; and exten ing depthwise, that is, inja direction toward thehandle, asumcie'nt distance to housethe a with freedom r tn wofn n torotate 'in. said recess. Above the recess [3 the guidechannel ne and areslidably 9 has a narrow slot [4 extending depthwise, and below saidrecess l3 the guide bore has a similar slot 15, said slots opening intothe recess l3. These slots are to receive the aligned trunnions I6 and Hof the worm 8, and terminate at such a point as to position the wormwith only its thread extending into the path of the teeth 1 of the stem6. The body I has aligned openings [8, through its opposite sides,exposing the sides of the worm, giving access for its manipulation.

In assembling the wrench, in the first instance the worm is introducedfrom the front into the recess l3 with its trunnions in the slots l4 andI5, and pushed back until the trunnions engage the ends of said slots.This positions the worm with its thread extending into the path of thestem 6 of the movable member 4. Next, the stem 6 is introduced into theguide groove 9 and pushed down until its toothed back face contacts thethread of the worm. Then the worm is turned, screwing the stem 6 downuntil it enters the guide bore 10, passes therethrough, and projectsfrom the lower end thereof. An end plate [9 is provided, having the samecross-sectional shape as the stem 6, but no thread teeth on its rearface, which is screwed congruently onto the projecting end of the stem6, making the movable member inseparable from the fixed member. The bodyor fixed member I is of greater thickness than the diameter of the wormin those regions which surround the openings l8, so that the worm isbelow the plane of the sides of the fixed member and protected frombeing battered through misuse.

The jaws 3 and 5 are formed with curved inner faces 20 and 2|,respectively, that of the upper jaw being concave and that of the lowerjaw being convex. Toothed jaw members 22 and 23 having correspondinglycurved outer faces, slide along the respective curved faces 20 and H ofthe upper and lower jaws, being retained and guided by dovetail tracks24 and 25, formed on the respective jaws 5 and 3, slidably supported bycomplementary dovetail grooves on the respective jaw members 22 and 23.The tracks terminate short of the free ends of the jaw members, so thatthey will not become marred by chance contact with the work in the useof the wrench. The curvature of the interfaces between the jaws and jawmembers'extends in an upward direction throughout the range of slidingmovement of the jaw members; that is, said grooves are struck from radiiwhich lie beyond the range of travel of the jaw members in a directiontoward the closed end of themouth of the wrench. The toothed faces 26and 21 are straight, the upper toothed face 26 being chordal withrespect to the grooved face 20, while the lower toothed face istangential with respect to the curved face 2!. Consequently, the upperjaw member 22 tapers toward its outer end, said outer end being thin,while the jaw member 23 tapers towards its inner end, its outer endbeing thick. Both toothed faces in the course of operation of the wrenchdeviate slightly from a relation of mutual parallelism. As the jawmembers 22 and 23 move inwardly upon the respective upwardly curvedguide tracks, the toothed face of each tilts in a clockwise direction,and as said jaw members move outwardly, their toothed faces tiltcounterclockwise.

The upper jaw member 22 is normally held in a neutral position by aspring 28, inserted in a bore in the slidable jaw and projected intothe' apex of a V-shaped notch in the upper jaw member. Fromthisposition, said jaw member can 4 move either inward or outward. When innew tral position, its outer end is slightly inward with respect to theouter end of the jaw 5, so that its thin end is protected and reinforcedby the overhang of said jaw.

The lower jaw member 23 is normally held in its foremost position bymeans of a spring 29, mounted in a bore in the fixed jaw 3 andprojecting into a notch in the lower jaw member. From thisposition thelower jaw member is yieldable inwardly. There is ample clearance betweenthe inner ends of the jaw members and the adjacent structure whichconstitutes the closed end of the wrench mouth to permit the necessaryrange of sliding movement of the jaw members.

When in normal inactive position, as shown in Figure 1, the toothed face2-6 of the upper jaw member 22 is inclined slightly downwardly towardthe plane of the toothed face 21 of the lower jawmeinber 23. The lowerjaw member normally projects outwardly beyond the upper jaw member,being complementary to the overhanging end of the movable jaw 5.

The wrench operates as follows: First, the mouth of the wrench is closeduntil its outer end is just too small to admit the pipe, as in Figure 1.Then the wrench is pressed against the pipe and pushed astride it by arectilinear movement, the upper jaw being pressed radially'towarcl thepipe to favor the movement of the upper jaw member preferentially to thelower jaw member. The first action is that the pipe pushes the upper jawmember back, causing it to ride up on its curved track. This widens thejaw mouth, since as the upper jaw member moves back, it also movesupwardly. Also, its toothed face tilts in a clockwise direction,admitting the pipe into the mouth of the wrench. The pipe may beintroduced as far into the mouth as may be desired, at least until thediameter of the pipe is some little distance inwardly of the end of theupper jaw member 22, as shown in Figure 2. There will never be a spacebetween the pipe and jaw members, for the upper jaw member constantlythrusts forwardly in a wedge-like manner, automatically taking up anylooseness between the jaw members and pipe.

Due to the fact that the lower jaw member projects beyond the upper jawmember, the point of tangency of the pipe with the toothed face 21 isquite a distance inwardly from the end of the lower jaw member.

Up to this time, no turning movement has been imparted to the wrench,but the toothed faces of both jaw members are in firm contact with thepipe, due to the automatic outwardly directed wedging action of theupper jaw member. Now the wrench is turned in a clockwise direction. Theimmediate result of this movement is to force the upper jaw memberoutwardly and the lower jaw member inwardly. Since the upper jaw membermoves down-hill when moving outwardly, while the lower jaw member movesup-hill in moving inwardly, the toothed faces 26 and 21 of therespective jaw members will move towards one another, forcibly embeddingtheir teeth more or-less into the pipe according to its hardness, toobtain a biting grip. In moving down-hill, the free end of the upper jawmember tilts downward, while in moving up-hill, the free end of thelower jaw member tilts upward. This mutual convergence of the jawsnarrows the mouth of the wrench to a width less than the diameter of thepipe, as shown in Figure 3, and prevents the pipe from slipping from thejaws, even though the toothed faces may be somewhat worn or clogged. Thefact that the wrench cannot escape from the pipe eliminates a dangerhazard, par..- ticularly when working on an overhead pipe.

Upon release of the wrench, the upper jaw member is urged inward, whilethe lower jaw member is urged outward, the biting grip upon the pipebeing released so that the wrench turns freely about the pipe, but theupper jaw member is constantly biased wedgingly outward by the spring28, so that both jaw members are maintained in firm contact with thewrench during its reverse movement, enabling the wrench to immediatelypick up its biting grip when it is pulled in a clockwise direction.

While I have in the above description disclosed what I believe to be apreferred and practical embodiment of the invention, it will beunderstood by those skilled in the art that the specific details ofconstruction and arrangement of parts, as shown, are by way of exampleand not to be construed as limiting the scope of the invention.

What I claim as my invention is:

1. Pipe wrench having upper and lower jaws defining themcuth of thewrench, the confronting faces of said jaws being upwardly curved in adirection from'their free ends towards the closed end of the wrenchmouth, the curvature of the upper jaw being concave and that of thelower jaw being convex, longitudinal track means on said curved faces,upper and lower jaw members having complementary curved faces engagingthe curved faces of said jaws, longitudinally slidable thereupon andretained by said track means, the opposite faces Of said jaw membersbeing planiform and toothed and so disposed with respect to therespective curved faces as to mutually converge toward their forwardends when the upper jaw member is in a forward position and the lowerjaw member in a rear position,

and being mutually slightly divergent toward their forward ends whenboth are in their forward positions.

2. Pipe wrench having upper and lower jaws defining the mouth of thewrench, the confronting faces of said jaws being upwardly curved in adirection from their free ends toward the closed end of the wrenchmouth, the curvature of the upper jaw being concave and that of thelower jaw being convex, longitudinal track means on said curved faces,upper and lower jaw members having complementary curved faces engagingthe curved faces of said jaws, longitudinally slidable thereupon andretained by said track means, the opposite faces of said jaw membersbeing planiform and toothed and so disposed with respect to therespective curved faces as to mutually converge toward their free endswhen the upper jaw member is in a forward position and the lower jawmember is in a rear position, and being mutually slightly divergenttoward their free ends when both are in their forward positions, aspring yieldably holding said upper jaw member in a neutral positionfrom which it can move forward or rearwardly, and a springyieldably'holding said lower jaw member in its foremost position.

3. Pipe wrench having upper and lower jaws defining the mouth of thewrench, the confronting faces of said jaws being upwardly curved in adirection from their free ends towards the closed end of the wrenchmouth, the curvature of the upper jaw being concave and that of thelower jaw being convex, longitudinal track means on said curved faces,upper and lower jaw members having complementary curved faces engagingthe curved faces of said jaws, longitudinally slidable thereupon andretained by said track means, the opposite faces of said jaw membersbeing planiform and toothed and so disposed with respect to therespective curved faces as to mutually converge toward their free endswhen the upper jaw member is in a forward position and the lower jawmember is in a rear position, and being mutually slightly divergenttoward their free ends when both are in their forward positions, aspring yieldably holding said upper jaw member in a neutral positionfrom which it can move forward or rearwardly, and a spring yieldablyholding said lower jaw member in its foremost position, said jaws beingeach externally convergent toward its free end, the forward end of saidupper jaw member being thin and when in foremost position being overhungby the free end of said upper jaw, the forward end of said lower jawmember being thick and when in foremost position extending beyond thefree end of said lower jaw.

4. Pipe wrench comprising a fixed member including a lower jaw, and acooperating movable member adjustable with respect to said fixed memberand including an upper jaw, said jaws defining the mouth of the wrench,the confronting faces of said jaws being upwardly curved in a directionfrom their free ends toward the closed end of the wrench mouth, thecurvature of the upper jaw being concave and that of the lower jaw beingconvex, longitudinal track means on said curved faces, upper and lowerjaw members having complementary curved faces engaging the curved facesof said jaws, longitudinally slidable thereupon and retained by saidtrack means, the opposite faces of said jaw members being planiform andtoothed, and so disposed with respect to the respective curved faces asto mutually converge toward their free ends when the upper jaw member isin forward position and the lower jaw member in a rear position, andbeing mutually slightly divergent toward their free ends when both arein their forward positions, a spring yieldably holding said upper jawmember in a neutral position from which it can move forward or rearwardand a spring yieldably holding said lower jaw member in its foremostposition, said jaws being each externally convergent toward its freeend, the forward end of said upper jaw member being thin and when inforemost position being overhung by the free end of said upper jaw, theforward end of said lower jaw member being thick, and when in itsforemost position extending beyond the free end of said lower jaw.

JOHN R. LEONARD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 454,896 Adams June 30, 1891577,770 Martin Feb. 23, 1897 595,473 Hall Dec. 14, 1897 955,893 MillerApr. 26, 1910 1,048,380 Youngguist Dec. 24, 1912 1,148,410 Smith July27, 1915 1,344,573 Barnes June 22, 1920 1,362,481 Dobbins Dec. 14, 19201,396,982 Ward Nov. 15, 1921

